Induction of specific anti-actin antibodies and their measurement by ELISA technique.

Using the ELISA technique we have been able to quantify antibodies directed against actin and to follow the kinetics of antibody production. Specific anti-actin antisera have been raised in rabbits by immunization with chemically modified white muscle rabbit actin. Two or three dinitrophenyl groups linked per actin molecule were sufficient to break natural tolerance, while linkage of three phosphorylcholine groups to actin was not.     

Effects of cilostazol on lipid and fatty acid metabolism

Abstract Cilostazol is a selective inhibitor of phosphodiesterase III with anti-platelet-aggregatory and vasodilating properties. Randomised, double-blind, placebo-controlled trials in 2702 patients with intermittent claudication demonstrated that cilostazol significantly increased walking distances compared with placebo. Furthermore, the agent has beneficial effects on the serum lipid profile and fatty acid composition in plasma. Consequently, cilostazol may be useful to prevent atherosclerosis from progressing by ameliorating lipid and fatty acid metabolism.     

Small epithelial cells in human liver cirrhosis exhibit features of hepatic stem-like cells: immunohistochemical,electron microscopic and immunoelectron microscopic findings

AIMS: To investigate whether cells with features similar to those of the oval cells of rodents and the small epithelial cells (SEC) recently described in certain human liver diseases, i.e. hepatic progenitor cells, also occur in human liver cirrhosis. METHODS AND RESULTS: Surgical specimens from 35 cases of hepatitis B virus-positive cirrhosis (30 cases containing hepatocellular carcinoma) were investigated by immunohistochemical staining for cytokeratin 7 and albumin. Electron microscopic investigations, and immunoelectron microscopic investigations using the same antibodies and a double-labelling technique were performed in 15 and seven cases, respectively. SEC were observed in proliferated bile ductules, at the margins of regenerating nodules and in the fibrous septa in all cases of cirrhosis. The SEC were morphologically similar to the SEC described previously, and to the oval cells seen in experimental hepatocarcinogenesis. They were characterized by their small size, oval shape, scanty electron-dense or electron-lucent cytoplasm, a high nucleo-cytoplasmic ratio, tonofilaments and intercellular junctions. Immunoelectron microscopy revealed that the SEC co-expressed cytokeratin 7 and albumin. Both relatively undifferentiated SEC and SEC with morphological and immunophenotypical signs of differentiation towards biliary epithelial cells and hepatocytes were found. CONCLUSIONS: SEC that exhibit morphological and immunophenotypical features of the SEC seen in certain other liver diseases are found in cirrhosis. These findings further support the hypothesis that a bipotent hepatic stem cell that may give rise to biliary epithelial cells and hepatocytes exists in the human liver.     

Renewal of the membrane complex of Schistosoma mansoni is closely associated with lipid metabolism

Metabolic pathways leading to lipid biosynthesis in four different developmental stages of Schistosoma mansoni were explored and quantified by incubation in the presence of labeled precursors in a chemically defined medium. At the schistosomulum stage and in male, female, or paired worms, glycerol and oleate incorporation into neutral lipids, mainly in the form of triacylglycerols, was greater than into phospholipids, whereas in 11-and 15-day-old worms, synthesis mainly led to phospholipids. Incorporation into phospholipids was recovered largely in phosphatidylcholine, and distribution into other phospholipids depended on the developmental stage. Incorporation of choline and ethanolamine into their respective phospholipids represented up to 15% of the parasitic phospholipid content. The formation of phosphatidylcholine by phosphatidylethanolamine methylation occurred mainly in the immature parasitic stages. Inositol incorporation was also measurable, whereas [14C]serine incorporation was low or undetectable. Addition of 1-palmitoyl-2-[14C]oleyl phosphatidylcholine revealed a very high uptake of this phospholipid by the immature stages but further metabolism was not detectable. In contrast, adult S. mansoni were completely unable to take up or absorb this exogenous phospholipid. The most striking aspect of this study was the relatively high metabolic activity in 11-day-old worms and the lower but sustained activity on day 15 and at the schistosomulum stage. By comparison, biosynthetic activity in adult S. mansoni, on which research studies have been focused until now, was very low. We also discuss the participation of lipid metabolism in the constant renewal of the membrane complex which is essential to parasitism by S. mansoni.     

The questionable use of albumin for the prevention of ovarian hyperstimulation syndrome in an IVF programme: a randomized placebo-controlled trial

BACKGROUND: The role of intravenous (IV) albumin administration in the prevention of ovarian hyperstimulation syndrome (OHSS) and in the improvement of IVF conception outcomes was evaluated in a prospective, randomized, placebo-controlled double blind study. METHODS: Ninety-eight women were enrolled in the study and were consecutively assigned to either a treatment group or a control group. Eleven patients were lost to follow-up after assignment. Of the remaining 87 women, 46 received albumin on the day of oocyte retrieval, and 41 received 0.9% sodium chloride solution as a placebo control. Outcome measures included OHSS incidence rates and pregnancy rates in the two trial groups. RESULTS: Four of the 46 patients in the study group developed severe OHSS and six developed moderate OHSS. In the control group, one of the 41 developed severe OHSS and five developed moderate OHSS. The difference in OHSS incidence rates between the two groups was not statistically significant [relative risk (RR) = 1.49, 95% CI = 0.59-3.73]. Fourteen patients (30%) in the intervention group conceived, compared with 16 patients (39%) in the control group. The difference in conception rates between the two groups was not statistically significant (RR = 0.78, 95% CI = 0.44-1.39). CONCLUSIONS: Albumin appears to have no positive effect on OHSS or conception rates, while its use carries the risk of undesirable side effects, including exacerbation of ascites in OHSS, nausea, vomiting, febrile reaction, allergic reaction, anaphylactic shock and risk of virus and prion transmission. We suggest that this form of treatment should not be included in the prevention of OHSS.     

The thymus as primary site for antigen-specific T suppressor cells in neonatally induced tolerance to bovine serum albumin

The ontogeny of antigen-specific T suppressor cells in thymus and spleen was analyzed in CBA/Ca mice which were rendered tolerant as neonates by subimmunogenic doses of bovine serum albumin (low-zone tolerance). Activity of T suppressor cells from those mice was assessed by an assay in which spleen cells from animals primed with fluorescein-conjugated human gamma globulin can be stimulated in vitro to produce IgG anti-fluorescein antibodies when cultured in the presence of fluorescein-conjugated bovine serum albumin. Carrier-specific T suppressor cells appear first in the thymus (day 10), and much later (day 30) in the spleen. The data are discussed in connection with the possible role of T suppressor cells during induction of tolerance in newborn mice.     

脂质、血红蛋白、胆红素标本对乙肝病毒DNA荧光定量测定的影响

目的:探讨脂血、高胆红素和溶血标本对乙肝病毒DNA(HBVDNA)荧光定量测定结果的影响。方法:将乙肝大三阳高脂血和非脂血、溶血血清和未溶血血清同时作HBVDNA荧光定量检测;将HBVDNA阴性黄疸血清和HBVDNA阴性正常血清与来自同一份乙肝大三阳血清混合,在相同条件下进行HBVDNA荧光定量。结果:乙肝大三阳溶血与未溶血样本HBVDNA含量都在同一数量级。乙肝大三阳高脂血的HBVDNA含量明显低于对照标本。高黄疸血清、正常对照血清与相同的HBVDNA阳性模板组合后所测得的HBVDNA结果无差异。结论:脂血对HBVD-NA定量测定有严重干扰;溶血样本、高胆红素样本对HBVDNA测定结果无影响。     

Serum contains a potent factor that decreases β-adrenergic receptor-stimulated L-type Ca2+ current in cardiac myocytes

L-type Ca²⁺ current (I _Ca) was measured in cultured atrial myocytes from hearts of adult guinea-pigs using whole-cell voltage clamp. Potentiation of I _Ca induced by -adrenergic stimulation (isoprenaline 2· 10^–7 M) could be completely antagonized by diluted sera (1100 v/v). Half-maximal inhibition of -receptorstimulated I _Ca occurred at about 11000. Basal I _Ca was not affected by serum. Atropine in a concentration (10^–6M) that completely antagonized the anti-adrenergic effect of acetylcholine (ACh, 2·10^–6 M) did not interfere with the effect of serum. In cells dialysed with cyclic adenosine monophosphate (cAMP)-containing (10^–4 M) pipette solution, potentiated I _Ca was insensitive to both ACh and serum. Preincubation of the myocytes with pertussis toxin almost completely abolished the anti-adrenergic effects of both ACh and serum. The potency of serum was not reduced by dialysis. It is concluded that serum contains a factor which, like ACh, inhibits -receptor-stimulated adenylyl cyclase via G_iprotein.A preliminary report of this work has appeared in abstract form [11]     

Generation of the eosinophil chemotactic factor (ECF) from various cell types by melittin

The peptide melittin, the main constituent of bee venom is a potent stimulus for the generation of an eosinophil chemotactic factor (ECF) from human polymorphonuclear neutrophils, rat mast cells and rat peritoneal cells depleted in mast cells. Optimal EFC induction required a sublytic activation of the cells. With each cell type the kinetics of ECF generation were similar in that after an early rise in activity a steep fall off occurred at later times of incubation suggesting a mechanism of inactivation. The induction of ECF by melittin is increased in the presence of calcium. The polar portion of the melittin molecule (aminoacids 20–26) is responsible for the generation of the chemotactic activity. Other peptides of honey bee venom such as the mast cell degranulating peptide (MCD) or apamine do not initiate ECF release. It appears that melittin leads to ECF induction via the phospholipase A₂-arachidonic acid dependent pathway of cell activation. Our data suggests that the lipid mediator ECF can be obtained from phagocytes and mast cells thus indicating the interdependence of inflammatory reactions.     

69,XXY伴严重生长迟缓及眼球突出病例的产前诊断

目的分析孕中期血清筛查数据和胎儿彩色多普勒与染色体异常之间的关系。方法对一孕中期血清产前筛查18三体风险1:10,血清Free-hCGβ异常减低(值为1.29ng/ml即0.08MOM),胎儿系统结构检查提示胎儿小于孕周,头腹围比(1.63)大于正常(1.25),上唇连续性中断延至鼻底的孕妇进行羊膜腔穿刺,抽取羊水进行细胞遗传学检查。结果羊水细胞染色体核型:69,XXY。结论中孕期妇女血清Free-hCGβ异常减低和胎儿头胸围发育不同步、胎儿唇腭裂提示胎儿染色体畸变可能,血清和超声联合筛查有助于染色体疾病的检出。